product loop woocommmerce re

function pro_grid_loop(){
//ob_start();
//wp_reset_postdata();
?>
<?php
        $arg = array(
        'post_type' => 'product',
        'posts_per_page' =>6,
        'product_cat' => 'best-seller'
        );
        $pro = new WP_Query($arg);
        ?>
        <div class="row grid_prod">
        <?php if ($pro->have_posts() ): ?>
        <?php while ($pro->have_posts() ) : ?>
        <?php $pro->the_post();
        global $product;
        $eid = get_the_ID();
        ?>
            <div class="col-md-4">
                <img width="300" height="300" src="<?php echo get_the_post_thumbnail_url($product_id);?>"/>
                <h2 class="singleProd_title"><?php echo $product->get_title(); ?></h2>
                <span class="woocommerce-Price-currencySymbol">$</span><?php echo $product->get_price(); ?></bdi></span>
            
            </div>
            <?php endwhile; ?>
                <?php endif;?>
            </div>
        <?php
wp_reset_postdata();
//return ''.ob_get_clean();
}
add_shortcode('best_product_grid', 'pro_grid_loop');